JPH0572953B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the catalytic reforming of gasolines of the type defined in the preamble of claim 1 under high pressure and high temperature.

Catalytic reforming is the most important method for producing Otto-fuels, which must constantly meet the high requirements for _antiknock properties in internal combustion engines with improved performance.

In catalytic reforming, naphthenes are dehydrogenated to aromatics, paraffins or naphthenes are isomerized, and paraffins undergo dehydrocyclization with evolution of hydrogen, in particular by processes which proceed under high pressure and high temperature. By hydrocracking, long hydrocarbon chains are broken down into hydrocarbons of short chain length, and hydrogen is added to the resulting olefin fragments to produce all short chain length paraffins. In these reactions, the net production of hydrogen as well as C ₁ -C ₄ -hydrocarbon compounds takes place. All of these other reactions that take place during reforming increase the antiknock properties of the resulting reformed gasoline, quantitatively indicated by the octane number expression, in the desired manner. Knocking strength is measured by the engine method or research method on test engines under standardized conditions and is expressed as engine octane number (MOZ) or research octane number (ROZ).

The octane number of n-heptane is by definition 0, and that of iso-octane is 100. Octane numbers greater than 100 are achieved by adding tetraethyl-lead to iso-octane.

In order to improve the anti-knock properties of carburetor fuel, it is desirable to limit the addition of lead compounds as much as possible, and there is a demand for carburetor fuels that exhibit high anti-knock properties without the addition of lead compounds.

In the known catalytic process for reforming gasoline, a noble metal catalyst such as platinum is supported on high-purity alumina (Al ₂ O ₃ ) as a carrier, possibly in addition to other metals such as rhenium. and used. The temperatures used are approximately 480 DEG to 550 DEG C. and the pressures are approximately 8 to 30 bar, the high hydrogen partial pressure serving to suppress deactivation of the catalyst by the formation of coke on the catalyst carrier. Lower pressures are advantageous for increasing the yield of modified products. Typical conditions for operating a reformer are e.g.
Processing), September 1980, p. 162. By the optimal method for regenerating the catalyst,
Replenishment of the catalyst is achieved, for example, by burning off the carbon on the catalyst in a so-called swing reactor, and also by flushing some of the catalyst out of a fluidized bed of catalyst maintained in the reformer. activity is maintained.

The pure hydrogen product produced during reforming is an important source for meeting the demand for hydrogen in refineries for various refining processes and other conversion processes.

In contrast, the evolution of C ₁ -C ₄ gases during reforming can be considered as the formation of by-products with correspondingly appreciable carbon losses.

The materials used for catalytic reforming are straight-run gasoline, i.e., fractions in the boiling range of gasoline obtained by various cracking processes (see ``Hydrocarbon Processing'', cited above). However, exon donor
Solvent coal liquefaction method (Exxon Donor Solvent)
Kohle-verflu¨ssigungsverfahren: EDS-method)
It has also been reported that the products in the naphtha boiling range obtained by catalytic reforming can be processed by catalytic reforming (Proc.
(See page 379).

For these reasons, in the case of the method of the type mentioned above, it is possible to increase the yield (C ₅₊ yield) of the liquid product of the reformer with improved antiknock value for use as an organic fuel, and The problem is to increase the hydrogen yield, which corresponds at least to the standards customary for the method, while maintaining the catalytic activity.

This problem is solved by the present invention. The essence of the invention lies in implementing the means of the characteristic part of claim 1.

It is advantageous to use a mixture of coal-sourced reforming substances, specific reformer supply substances, and petroleum-derived reforming substances in a weight ratio of 20:80 to 40:60. It is.

Typical petroleum-based gasoline used for reforming contains, for example, 44% by weight paraffin, 41% by weight monocycloparaffin, and 2% by weight
of dicycloparaffin and 13% by weight of aromatic compounds.

The light oil of coal origin or the Ruhr region bitumen obtained by liquefied hydrogenation according to the above hydrogenation process in the distillate phase and the gas phase, which is used according to the invention as the material used for reforming. The gasoline produced differs from petroleum-based reforming materials mainly in that it has a low paraffin content and a high monocycloparaffin content.

In liquid-phase hydrogenation at high pressures and temperatures, pulverized coal is annealed with ammaic oil, optionally with the addition of catalytically active substances, and gaseous The reaction is carried out with the addition of hydrogen, the residue is separated from the effluent from the distillate liquid phase hydrogenation stage, the residue-free volatile product is cooled, and the fraction which may serve as uncooked oil is produced. Separate, Al ₂ O ₃ or
Ni/Mo supported on a support made of Al ₂ O ₃ −SiO ₂
- or Co/Mo-catalyzed gas phase hydrogenation and a refined naphtha or gasoline fraction originating from coal is obtained. These fractions are used as such or after further hydro-processing steps for the specific reforming required. Another suitable use material is distillate-liquid-phase hydrogenation and - if necessary, high-boiling components by partial condensation, while maintaining sufficient process pressure and possibly also process temperature. In this method of gas-phase hydrogenation, the oil in the coal can be obtained by paraffinization or hydrocracking and separation of the fraction occurring in the gasoline boiling range.

Of course, it should be noted that the dehydrogenation reaction of monocycloparaffins, which can be considered as the main reaction in the reforming of gasoline fractions originating from coal, is a strongly endothermic reaction. The materials used, which mainly consist of gasoline and naphtha fractions of coal origin, can be adapted to reformers designed for ordinary gasoline fractions of petroleum origin, with corresponding preheating systems. cannot be supplied without The preheating system is expanded to accommodate the heat of reaction required when using mixtures containing more than about 40% by weight of coal-derived gasoline fractions.

The inventors have demonstrated that by the process according to the invention not only is it possible to produce ottofuels with excellent use properties, in particular improved anti-knock properties, but also a particularly technically advantageous method of operating the reforming process is possible. I discovered that.

This is evident in the high C ₅₊ yields as well as the high hydrogen yields and the correspondingly reduced amount of undesired C ₁ to _{C 4} gases formed under the same reforming conditions.
The catalyst residence time, which is characteristic of the desired activity of a platinum catalyst supported on a support consisting of, for example, Al ₂ O ₃ , is also advantageously influenced.

Engine octane number (MOZ) or research octane number (ROZ) is taken as the ordinate and
In Figures 1 or 2 of the drawings with C ₅₊ -yield (% by weight) on the abscissa, the C ₅₊ -yield and octane number can be determined from the curves applied to various mixtures of substances used for reforming. The improvements achieved can be read. The three curves in Figure 1 are, from bottom to top, a commonly used oil-based gasoline (comparative example) and an 80:20 ratio of such gasoline to a coal-based reforming feed. weight ratio mixture and
This corresponds to a substance used for modification composed at a weight ratio of 60:40.

The three curves in Figure 2 also relate to similar compositions.

The curves according to Figures 1 or 2 are due to the reforming experimental conditions described below: pressure 30 bar, temperature 490 °C, catalyst loading (WHSV) 1-4 Kg (feed)/Kg (catalyst).hr. Individual values of catalyst loading:
1, 2 or 4).

The mixture used for reforming with a weight ratio of 60:40 of petroleum-origin gasoline and coal-origin gasoline is compared to such a mixture with a weight ratio of 80:20 and purely petroleum-origin. It can be seen that higher octane numbers and higher C ₅₊ -yields are achieved compared to gasoline, respectively.

For example, according to FIG. 2, a C ₅₊ -yield of 79% by weight is achieved with ordinary gasoline as the reforming material at an ROZ of about 97 or less.

Under the same reforming experimental conditions, the relationship between petroleum-sourced gasoline and coal-sourced reforming feed
80:20 − mixture with a C ₅₊ yield of approximately 83% by weight
Achieved under ROZ values of 97 or higher.

85% by weight C ₅₊ when using a 60:40 mixture (by weight) of oil-based reforming feed and coal-based reforming feed.
- Yields and ROZ of approximately 98% are achieved.

Furthermore, high hydrogen yields have been found in the case of the mixtures used according to the invention.

On the premise that the high boiling point dicycloparaffin component in the used fraction derived from coal is kept within the range applicable to the gasoline fraction derived from petroleum by determining the appropriate boiling point classification. The catalyst standing time is quite satisfactory under comparable catalyst activity.

In order to adjust the octane number when using the mixture used according to the invention to the same specific product as is required for use as an ottofuel in a reformed product of purely petroleum origin, It is even possible to reduce the stringency of the modification step.

[Brief explanation of the drawing]

1 and 2 show the curves of C ₅₊ -yield and octane number achieved by the reforming carried out on the reforming mixture used according to the invention and on the comparative reforming material. It is written.

Claims (1)

[Claims] 1. A claim for catalytic reforming of straight-run gasoline, gasoline, or naphtha gasoline obtained by steam cracking, fluidized catalytic cracking, or hydrocracking under high pressure and high temperature. Afterwards, refined coal gas oil, gas oil obtained by oil-in-coal refining, gasoline obtained by hydrocracking of oil-in-oil from coal, or all thermal separator head products in the hydrogenation of coal are refined. characterized in that a mixture of a reforming substance of coal origin and a reforming substance of petroleum origin is used as the reforming feed consisting of the group of gasolines produced during Catalytic reforming method for gasoline. 2. A patent claim that uses a mixture of a petroleum-based reforming substance, a specific reforming feed, and a petroleum-derived reforming substance in a weight ratio of 20:80 to 40:60. The method for catalytic reforming of gasoline according to item 1.